<html>
<body>
Block IDs and references need to follow the AsciiDoc pattern conventions.
<br>
They must start with a character, <code>_</code> or <code>:</code> that can be followed by any character, number or
<code>_</code>, <code>:</code>, <code>-</code>, <code>.</code>.
<br>
Blanks are not allowed.
<!-- tooltip end -->
While IDs of style <code>[[id]]</code> don't allow for characters like <code>?</code> and <code>!</code>, IDs in the
style of <code>[#id]</code>
do. This is confusing, therefore this plugin advocates to not use these characters in any ID.
</body>
</html>
